JPH02279820A - Method of laying pile - Google Patents

Abstract

PURPOSE:To increase the bearing force of a pile by drawing up an auger after a steel pipe casing with a blade and an internal auger screw excavate up to a bearing hard ground to remove earth, and reversing the casing to remove excavated soil while sending it down. CONSTITUTION:Excavation is made from the ground surface to a bearing hard ground while driving forward a steel pipe casing 2 having a spiral blade to the peripheral surface and an auger screw fitting and inserting thereinto. The casing 2 and auger screw 3 are provided to a driving machine 6 of a slider 5 sliding a leader mast 4 of a crawler heavy machine as a guide up and down so that they are capable of loading and unloading, and they are respectively capable of moving right, left, forward and reverse. After they reach the bearing hard ground, the forward is stopped to release the connection of the casing 2 and the driving machine 6, and the auger screw 3 is drawn up. The removed earth (a) around the casing 2 on the ground is delivered down to the underground with the spiral blade 1 to consolidate around a pile A. According to the constitution, the pile A can exhibit remarkable bearing force.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a pile embedding method.

[Conventional technology]

Conventionally, piles are embedded in the ground by repeatedly hitting the head of the pile, or by drilling from the ground to an underground mold plate using an auger screw, and then inserting an auger screw into the mold plate. After the tip of the auger reaches the top of the hole, the auger screw, which has stopped rotating, is pulled up and the soil in the excavated hole is removed.
After that, a method of inserting and embedding piles into the drilled holes has been adopted.

[Problem to be solved by the invention]

In the case of the method of applying a blow to the head of the pile, there was a problem in that it produced severe noise and vibration, making it almost impossible to perform construction in urban areas.

Furthermore, in the case of a method in which a pile is inserted into a hole drilled while injecting cement milk using an auger screw, there are problems in that the bearing capacity of the pile cannot be confirmed and the upper limit of the bearing capacity is small.

Furthermore, when the piles were inserted into the borehole, the muddy water mixed with the excavated soil and cement milk in the borehole overflowed, causing a major problem due to industrial waste in the form of muddy water and muddy soil.

(Means for Solving the Problems) In order to solve the above problems, the present invention provides a steel pipe casing having spiral blades on the outer periphery and an auger screw inserted into the casing, each of which is rotated in the normal direction. After excavating from the ground to the underground support platform, each drive is stopped and the auger screw is pulled up while the excavated soil in the casing is held by the blades of the auger screw and discharged. A pile embedding method involves inserting a pile into a casing, and then removing the casing while driving the casing in reverse while transporting the excavated soil.If the pile is hollow, the tip of the pile is closed and the bottom of the hollow is struck. In addition, a pile embedding method is used in which the pile tip reaches the mold board.

[Effect]

A suspended pile is inserted into the excavated casing, and then the casing is driven in reverse while the casing is removed, and as the casing is driven in reverse, the excavated soil is forced into the ground by a spiral blade. while consolidating the area around the pile and increasing the friction around the pile.

If the pit is hollow and cylindrical, the pile tip is closed, and after the pile is inserted, a drop hammer inserted into the pit is used to hit the bottom of the pit, causing the pile tip to reach the form plate, thereby increasing the supporting force.

(Example) A steel pipe casing 2 having a spiral blade 1 on the outer periphery and an auger screw 3 fitted into the casing 2 are each rotated in the normal direction while being supported underground from the ground as shown in FIG. Excavate to the hard bed.

The above casing 2 and auger screw 3 are
As shown in the figure, a drive mechanism 6 for a slider 5 that slides vertically using the leader mast 4 of the crawler heavy equipment as a guide.
The casing 2 rotates counterclockwise, the auger screw 3 rotates clockwise in the normal direction, and can be driven in reverse as desired.

Further, although the spiral blade 1 is provided along the entire length of the outer circumference of the casing 2 in the illustrated case, it may be provided partially.

Next, as shown in Fig. 3, after the above-mentioned excavation reaches the supporting mold plate, each normal rotation drive is stopped, and then the connection between the casing 2 and the drive machine 6 is released, and the slider S is slid upward. While doing so, pull up the auger screw 3 as shown in FIG.

At this time, the excavated soil a in the casing 2 is held by the blades of the auger screw 3 and discharged.

Thereafter, as shown in FIG. 5, the suspended ready-made pile A is inserted into the casing 2.

After that, the upper end of the casing 2 is connected to the drive machine 6, and the casing 2 is pulled up while being rotated in the reverse direction by the operation of the drive machine 6.

At this time, casing 2J on the ground! ! The excavated soil a is sent down into the ground by the spiral blade 1, and as shown in FIG. 8, the area around the drag A is compacted, and the friction around the drag A is significantly exerted.

As a general rule, excavated soil is used as the soil for down-consolidation, but depending on the geology, true sand, general sand, or a dry mixture of cement and sand may be used.

Also, when the auger screw is pulled up, an appropriate amount of a richly mixed cement-based hardening solution may be filled into the bottom of the excavation hole using the passage provided in the shaft center of the auger screw.

In addition, as shown in Figure 12, when using anti-A made of reinforced concrete with flanges, the area between the flanges is completely compacted to increase the friction area, and as shown in Figure 13, the pile tip By using an expanded pile A whose side diameter is larger than the diameter of the other parts, significant bearing capacity can be obtained.

Furthermore, if anti-A is a hollow cylinder that is not solid as shown in FIG.
Close the pile tip.

To close the pile tip, as shown in FIGS. 9 and 10, the peripheral edge of the bottom plate 8 is overlapped with the anti-A end ring 7, and the port 9 inserted through the peripheral edge of the bottom plate 8 is inserted into the screw of the ring 7. A method such as screwing into the hole or welding the peripheral edges of the ring 7 and the bottom plate 8 after screwing the bolt 9 is adopted.

In addition, by providing a protruding plate 10 in the shape of a 7-shape, such as a flat cross, as shown in the figure, on the bottom surface of the bottom plate 8, the protrusion becomes larger toward the center. Pile anti-A can be driven in.

The hollow resistor A is connected to the casing 2 as shown in FIG.
then insert the drop hammer 11 into the hollow anti-A
is inserted, and while applying a blow to the bottom plate 8 by the vertical movement of the drop hammer 11, the tip of the pile with resistance A reaches (bites into) the supporting mold board as shown in FIG. Make it work.

In the case of a solid pile, when the pillar tip is inserted into the upper end of the casing and the pile is dropped, the pile tip can reach the mold board by its own weight because of its large weight.

(Effects) As described above, according to the pile burying method according to the present invention,
It is possible to eliminate problems caused by noise and drive, and
Since the area around the pile is consolidated by the soil falling when the casing is pulled up, the friction around the pile is increased and significant bearing capacity can be demonstrated.

In addition, if the pile is hollow, the pile tip is closed and a blow is applied to the bottom of the hollow to force the pile tip into the mold plate, increasing the bearing capacity and making it easy to check the pile's bearing capacity. At the same time, since the impact occurs underground, the noise problem is also solved.

[Brief explanation of drawings]

The drawings show the pile burying method according to the present invention, and are
The figure is a side view of the excavator, Figures 2 to 8 are vertical front views showing the pile burying process, Figure 9 is an enlarged front view of the pile tip,
Fig. 0 is a bottom view of the same as above, Fig. 11 is a longitudinal sectional front view showing a solid pile, Fig. 12 is a longitudinal sectional front view showing a flanged pile, and Fig. 13 is a longitudinal sectional front view showing an expanded bottom pile. A...Pile, 1...Spiral blade, 2...Casing, 3...Auger screw 8...A plate, 11...
...drop hammer. Figure 6 Figure 7 Figure 8

Claims (2)

[Claims] (1) A steel pipe casing with spiral blades on the outer periphery;
After excavating from the ground to the underground support platform while driving the auger screws fitted in the casing in normal rotation, each drive is stopped and the excavated soil in the casing is removed by the auger screws while pulling up the auger screws. A method for burying piles in which soil is held up by screw blades and removed, the pile is then inserted into an empty casing, and then the casing is driven in reverse to transport the excavated soil and remove the casing. (2) The method for burying a pile according to claim (1), characterized in that when the pile is hollow, the tip of the pile is closed and a blow is applied to the bottom of the hollow.